1. Field of the Invention
This invention relates to a data sending/receiving method and apparatus, a data receiving apparatus and a data sending apparatus. More particularly, it relates to a data sending/receiving method and apparatus configured for sending and receiving data, a data receiving apparatus and a data sending apparatus.
2. Description of the Related Art
With improvement in the technique of compressing video signals or speech signals or in the digital signal processing technique in the field of broadcasting or communication, it has become possible to realize services of distributing digital data, such as video on demand (VOD) or music on demand (MOD).
Up to now, as an example of service configurations of furnishing digital data, a so-called push type service is being offered, in which the receiving side specifies a particular genre to the host side over the Internet and in which the host side retrieves data falling under the genre from a data base to sequentially transfer the retrieved data in succession to the receiving side.
However, in the conventional data transmission/reception system, there lacks up to now a system of automatically downloading data of the new information, put on sale or publicized only of late, on the reception side. For example, in the conventional MOD system, there lacks a system of downloading data on new musical numbers on the reception side. In the conventional MOD system, there lacks a system for permitting the reception side to switch between the low quality reproduction and the high quality reproduction of data on new musical numbers. In addition, the conventional MOD system is no other than a system in which a user pays fee unexceptionally for data acquisition. On the contrary, there has not been known to data a system in which a portion of a new musical number is heard on trial and a user pays only the fee for the number which has suited to his or her liking in order to acquire the data for the new musical number in its entirety.